Here "arm" represents power. AT: "Destroy the power of the wicked and evil man" or "Make the wicked and evil man weak" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Making someone account for his evil deeds represents punishing him. AT: "Punish him for the evil things he has done" (See: [[rc://en/ta/man/translate/figs-metonymy]])